feat: add folloers/following list

internal/repository/social_graph_repo.go

@@ -93,6 +93,66 @@ func (r *FollowRepo) Status(ctx context.Context, followerID, followingID string)
 }
 
 // CountFollowers counts accepted edges pointing at userID.
+// ListFollowers returns the accepted followers of userID (users who follow
+// them), newest first, optionally filtered by a name/handle search `q`.
+// Returns the page plus the total matching count (for pagination).
+func (r *FollowRepo) ListFollowers(ctx context.Context, userID, q string, limit, offset int) ([]model.UserSummary, int, error) {
+	return r.listRelations(ctx, "f.following_id = $1", "f.follower_id", userID, q, limit, offset)
+}
+
+// ListFollowing returns the users userID follows (accepted), newest first,
+// optionally filtered by `q`. Returns the page plus the total count.
+func (r *FollowRepo) ListFollowing(ctx context.Context, userID, q string, limit, offset int) ([]model.UserSummary, int, error) {
+	return r.listRelations(ctx, "f.follower_id = $1", "f.following_id", userID, q, limit, offset)
+}
+
+// listRelations powers both directions: `whereOwn` pins the row to userID on
+// one side, `joinCol` is the follows column holding the *other* user (the one
+// we join to users and return). `q` filters by name/handle (ILIKE); empty `q`
+// disables the filter. The column expressions are fixed internal constants —
+// never user input — so this stays injection-safe.
+func (r *FollowRepo) listRelations(
+	ctx context.Context, whereOwn, joinCol, userID, q string, limit, offset int,
+) ([]model.UserSummary, int, error) {
+	like := "%" + q + "%"
+
+	var total int
+	countSQL := `
+		SELECT count(*)
+		FROM follows f JOIN users u ON u.id = ` + joinCol + `
+		WHERE ` + whereOwn + ` AND f.status = 'accepted'
+		  AND ($2 = '' OR u.name ILIKE $3 OR u.handle ILIKE $3)`
+	if err := r.pg.Pool.QueryRow(ctx, countSQL, userID, q, like).Scan(&total); err != nil {
+		return nil, 0, fmt.Errorf("count relations: %w", err)
+	}
+	if total == 0 {
+		return []model.UserSummary{}, 0, nil
+	}
+
+	listSQL := `
+		SELECT u.handle, u.name, u.avatar_url
+		FROM follows f JOIN users u ON u.id = ` + joinCol + `
+		WHERE ` + whereOwn + ` AND f.status = 'accepted'
+		  AND ($2 = '' OR u.name ILIKE $3 OR u.handle ILIKE $3)
+		ORDER BY f.created_at DESC, u.handle ASC
+		LIMIT $4 OFFSET $5`
+	rows, err := r.pg.Pool.Query(ctx, listSQL, userID, q, like, limit, offset)
+	if err != nil {
+		return nil, 0, fmt.Errorf("list relations: %w", err)
+	}
+	defer rows.Close()
+
+	out := make([]model.UserSummary, 0, limit)
+	for rows.Next() {
+		var s model.UserSummary
+		if err := rows.Scan(&s.Handle, &s.Name, &s.AvatarURL); err != nil {
+			return nil, 0, fmt.Errorf("scan relation: %w", err)
+		}
+		out = append(out, s)
+	}
+	return out, total, rows.Err()
+}
+
 func (r *FollowRepo) CountFollowers(ctx context.Context, userID string) (int, error) {
 	var n int
 	err := r.pg.Pool.QueryRow(ctx, `